Olympic champion Usain Bolt caught in bed with Brazilian student

Usain Bolt has been photographed in bed with a Brazilian student in Rio amid rumours he would be marrying his girlfriend Kasi Bennett after the Olympics.

Jady Duarte, 20, shared pictures of the topless athlete on Whatsapp.

One photo shows the Jamaican gold medallist kissing the woman's cheek and, in another, he is posing with his arm around her.

Miss Duarte tweeted in Portuguese to say her night with the sprinter was"not a big deal" and "normal", admitting she had not realised who the athlete was until her friend pointed it out.

Bolt– who has been dating his Jamaican girlfriend Kasi Bennett for two years – was also photographed dancing with another woman during his 30th birthday in Rio.

This comes a day after the athlete's sister, Christine Bolt-Hylton, told The Sun she that Bolt and his girlfriend are serious and expects the couple to get engaged on his return to the UK.

"[The impact] is very negative," she told Brazilian news site EXTRA. "I never wanted to be famous, I'm dying of shame."

The revelation may not have negative consequences for Bolt, who revealed in the Daily Telegraph that he believed cheating was acceptable.

"Jamaican culture is different, when you look at women and men having more than one [partner], it’s different," he said. "I’ve noticed that in Britain, every famous person, as soon as they get famous, they have to get married – like, it’s a rule. And I’m like, that’s not fair!'"

He also said, as a celebrity, it was difficult to "stay with one woman" when there was temptation from others.

"It’s hard for you to stay with one woman because girls are literally just throwing themselves at you," he said. " And that’s unfair to us guys – it’s hard to say no, you know what I mean? "

Bolt, who has not verified the photographs, has been approached for comment.